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Updates: Many topics are permanent, so may be updated to any material, for add or correct info.
Get more info: Since the beginning this site tryes to be a compilation center of the best sources for the JD800. Not a copy.
So please, visit the sites at the Links section for lots of much more very good information.

quinta-feira, 24 de maio de 2012

Rick Wakeman with a JD-800 at stage

I´m looking to find some pictures/videos of Master Rick with his JD-800.

Here, Rick Wakeman in 2009, playing live in Lugano.

The Roland JD-800 is in the center on top of image. The Moog is just at left.

Vol. 1- Live in Lugano

And here in another moment:

Master Rick Wakeman is an English keyboard player, composer, and songwriter
best known as the keyboardist for progressive rock group Yes.
Foto: StarCards


segunda-feira, 7 de maio de 2012

JD-800 Aftertouch Modification

Use the full range of aftertouch without straining your fingers.

This is a Mod to the JD-800 circuit. Do it at your own risk.

All JD-800 users knows we need to put a lot of pressure to use the aftertouch.

As someone sayd: one needs to stand on the keyboard to get an effect.

I took here the work of two great guys from the JD-800 Tech group. As I know, they had many messages about this work and here is the result with comments from both.

Preben Friis, synth lover an expert in electronics who explain how to do a simple mod to make the aftertouch become better, really light to play.

, a guy who have great merits and a lovely work and story.

From now, I merge material from both and something more, including one or two words of mine.

The Idea:


In basic, just change how the circuit "feel" the input value.
A 270 kOhm resistor across R27 will make it possible to use full range of aftertouch without straining your fingers.

R27 position.

Please read all the comments before doing anything you will repent! (LOL)

I poked around with a multimeter on the aftertouch circuit today. The pressure
ribbon starts out at 150 kOhm and by full pressure it is around 1 kOhm...

Shunting the ribbon will make it possible to move the threshold to make it start

earlier but will not make it more sensitive.


This is a modification you can do inside the JD if you are comfortable with a soldering iron that makes the aftertouch much more responsive.

This mod might require to unsolder a SMD resistor ... not something for people with ten thumbs.
For sure you can ask an electronics technician to perform this modification.

About opening the JD-800:

Removing all screws may do your internal components fall.
You must remove only the screws AROUND the bottom and two screws in the center line, they are at 1/4 from side, and may be you can see a few bigger hole where thy fit to.
Sometimes the bottm have some "dust" acting like glue to.

How to remove the panel.
JD-800 Manual. (click to enlarge)
Source: Roland Co.

The Solution:


Thanks to Gwydion Elderwyn I received exactly what I needed to calculate and test a better modification of the aftertouch circuit in the JD-800.
The short version: 
Change resistor R27 to 120 kOhm instead of 220 kOhm. Done.
The long version:
Since SMD components are very difficult to remove, and I did not have any SMD components at hand, I chose to solder a 270 kOhm resistor parallel with R27. 
R27 is located on the mainboard in the left corner right by the ribbon cable to the keyboard.
The picture shows my "huge" resistor piggyback on R27. It is not very pretty, but it works! 

Image by: Preben Friis

Actually the picture shows a 100k resistor, which was the first one I tried, but that made the aftertouch sensitivity too light. I could easily press the aftertouch from 0 to 127 with my pinkie finger. The 270k resistor is in my opinion the best value. If I use my pinkie with this value it allmost hurts to press it to max. Feel free to experiment - Reasonable values are in the range from 100k to about 1M
Find a soldering iron with a very thin tip and add a little solder to the two pads on R27 first. Then cut and bend the legs of the new resistor to fit across it and add a little solder blob to the legs of it. Hold the new resistor in position with a set of pliers and touch the iron to the legs of the resistor. This should melt both solder blobs to one and the connection is made. Repeat for the other side.
The smaller the better: 
A 1/8W resistor would be preferred over a 1/4W. 
Smaller resistors have thinner legs and that makes them easier to solder to the SMD resistor.
(Acutally I'm currently using a 1/2W resistor and it is BIG!).

The tolerance does not matter much. You can use 220k or 180k if you really want to use the full aftertouch range when playing monofonic lines.
An alternate idea:
Marc (also suggest using a trimmer instead of a fixed resistor:
What I'd like to do instead on this mod is replace the resistor by a lower value, cut the trace next to it and connect a 500Kohm trimmer pot with modding wire (26-28Awg) and have it adjustable. 
I imagine not every aftertouch ribbon has exactly the same value, so this would make it tweekable. Nice thing is if the value of the ribbon changes in time, all you have to do it open it up and adjust it a little. The fixed resistor is there as safeguard so the value doesnt go below a safe value and draws too much current.
Also, I would not connect a pot in parallel with the current value. The response of the pot would not be linear at all, and hard to adjust. 

Another mod using the same idea:

See that was placed a wire connecting the potentiometer (at left) to position R27 in the circuit board.
Foto: Yuri Alfons Peeters Charlotte

Remember to power off before you solder anything... 
If you connect the resistor properly without shorting anything there is no risk involved in this modification. The current in the pressure ribbon will be double from around 40 uA to 80 uA, but those currents are still very far from anything that can destroy any components.

I can tell you, that a well adjusted aftertouch is almost like getting a new synth. Many of the factory sounds is way more fun to play around with, when you can change the sound by a light pressure. 
For example, try for instance patch I-22, Classic Sweeper .. 
Thanks again Gwydion Elderwyn, I couldn't have done this without your help :-)
Have fun.

Preben Friis

The Circuit and the mods

As we say here in Georgia, WEEEEEE HAAAAAA!

Thanks Preben!  This mod was easy and it works great!  I used the 270k and find the aftertouch to now be similar to my K2000.

Most excellent.  Kinda makes you wonder why Roland didn’t get it right in the first place.

Jim Combs



domingo, 6 de maio de 2012

Sorting Out Flats JD800 Sticky Key - Red Glue

In the Harmony Central site, the Keys, Synths & Samples forum is the one of the best group about synths and synth players I have found.

From there is this great post about one of the famous problems of the JD-800: the sticky key, also know as the Red glue problem. .

Link to the original topic: ***Flats-JD800-Sticky-Key-Session-***

Topics created by Flat Earth - Vive La Synthesizer! You find him at

***Flats JD800 Sticky Key Session ***

Heres a very quick guide to sorting out the infamous Roland JD800 'Sticky key problem'
As you are only allowed 10 images, I´m sorry if it is not too clear.

Remove the 8 screws located under the ‘ROLAND’ logo on the back of the JD800. then the 2 screws on the underside of the JD and the 3 screws at either ends (left image). The top facia of the synth will open up like a bonnet revealing the circuitry and keyboard (a strap on the left hand side prevents the lid/facia from falling back)

The keyboard can now be removed. Firstly, gently prize out the ribbon connector that connects the keyboard to the motherboard (left image). Using a side-to-side motion (don’t force it!), then unscrew the 6 gold screws running along the top of the keyboard chassis (right image), and the 5 screws underneath the synth (holding the keyboard steady)

The whole keyboard assembly should slide forward easily now. Before taking apart the keyboard, its best to lay it face down on a towel or soft cloth (keep a dish handy for small parts)

On the back of the metal keyboard chassis, there are 5 black strips securing each octave of the keys. Remove 1 strip and the one octave of keys at a time. A knife or flat screwdriver can be inserted under the strip to gently prise it off. (See above right)

After the strip has been removed, each key can be taken out by gently pushing it out. (After each key has been removed, take out each corresponding metal spring clip that is underneath the key, and put it somewhere safe. Put all the keys in order, upside down on a piece of board. (Right image)

At this point, you should be able to see the ‘Red glue’ that is causing the sticky key (red glue) problem.
I found in my case, all the problems seem to emanate from the glue leaking from the ‘black keys’. The glue had dripped down onto the damping strip & between the keys themselves. (see below)

The ‘Red glue’ can be cleaned easily from between the keys. The glue that has fouled the damping strip on the other hand (left image), has to be gently scraped off with a scalpel. I found some of the glue had been absorbed by the damping strip. I was able to cut it out, and then ‘fluff up’ the resulting hole. If the damping strip were too heavily saturated with glue, it would be a better idea to replace it (if Roland can still supply this).

Once all the glue has been cleaned away, it’s worth cleaning the contacts. Just remove the 5 grey rubber contact suspension mats and clean the whole strip with a light tissue doused in cleaning fluid. (Be careful removing these mats, as the small rubber securing cones can tear easily!)

The keyboard section can now be re-assembled and tested.

I found that putting a thin layer of hot glue over the ‘red glue’ in the black keys could prevent further leakage in the future. But not too much as to make the key too heavy.

Hope this is of use to anybody experiencing similar problems.

Additional comments from that topic and very useful info from the topic follow. (Edited)

Comment by Don Solaris - Certified Synth Maniac

Unfortunately, cleaning of damping strip from bottom side is not that easy. And the only solution (after you clear keys and before you put them back) is to take a small piece of Post-It paper and put it right over the glue. Glue will hold it, and key won't be sticky anymore.

Same can be applied to top side of damping strip as in many cases, the glue already penetrated it deep enough, that you can no longer cut it out with scalpel.

Comment by  MarkShovel2

I found it was essential to get the metal spring clips uniformally seated on each key. I had a few black keys that were stiff. I observed that the metal clips were not correctly seated into the top of the key. When correctly seated, everything is very uniform. The action now approaches my two V-Synths.

Comment by Flat Earth

Id thought of putting a small piece of thin plastic or paper over the saturated parts of the damping strip, but after gently cutting it out, i was able to 'fluff' it up, with a needle back to a pretty good state.

Comment by 4thtry

As in your case the black keys were causing the majority of the problem. I used a tube of silicon instead of hot glue to try and seal in the offending red glue. I had to be careful not to add too much or the little metal stopper with the rubber jacket would come in contact and add unwanted friction.

Comment by Flat Earth

when i inserted the hot glue, i had to be careful not to put too much in. I found a small blob either side of the weight did the trick. Used a small screw driver to spread it over the red glue, but you have to be quick, the hot glue sets quite quickly.

I didnt do the white keys btw. Even if they had 'leaked', they wouldnt cause any problems with the keybed mech as they arnt above it. I will be keeping an eye on them though.

Comment by Flat Earth


After repairing the keyboard action (which now plays super smooth) i found I had a few dead notes. I thought the culprit may well be the rubber dome key contacts, so i took it apart again and made a note of which keys failed to play. I then swapped one of the 5 grey strips with another and checked to see if the key played. **BINGO** they worked. They rubber strip must have worn out. Its best to replace all 5, but remember, the 5th strip (top octave) is different to the lower 4 octave strips. It has 13 contacts rather then 12 like on the other lower octaves. Take this into account when ordering replacements. 


Another topic for the Red Glue problem is: One fix for red glue problem.


sexta-feira, 4 de maio de 2012

Mac Logic Studio: a little Roland JD800 Environment

This is for the Mac users of the Logic Studio Pro.

I found this at forum posted by Virgo.

Roland JD800 Environment

Postby virgo » Mon Mar 26, 2012 4:13 am

As promised in this thread (click to see post), here`s my little JD800 environment.

I will probably add the FX section sometime.

Original download link: 
JD800 Environment (590.51 KiB)


Note: Logic Studio Copyright © 2012 Apple Inc.


Article Quote: Jean-Michel Jarre's Comment

Not sure, at right top, appears to be the JD800 and a Nord.
Foto: Music and You

This is a quote from the great article: Synth-Aesthesia: Jean-Michel Jarre's Favorite Keys by Patrick Thévenin, published at site 03.05.2012.

Jean-Michel Jarre speaks to French journalist Patrick Thévenin about ten of his favourite synthesizers.

(A very nice list)

E.M.S VCS 3 (1969)
ARP 2600 (1971)
ARP 2500 (1969)
RMI Keyboard Computer (1974)
EMINENT 310 (1970)
Teenage Engineering OP-1 (2011)

Roland JD-800 (1991)
This was the next synth to follow the DX7 philosophy and the approach initiated by Japanese synths, which was going to financially sink all of the American makers. I included it in my list because it was one of the first polyphonic Japanese synths that managed to resemble an analogue synth, although what I hated about the DX7 was that it left you thinking that electronic music only aimed to imitate the sounds of acoustic instruments. With the JD-800, you could modify the sound, as you can on an ARP or a Moog, but with a Japanese sound quality, which in some respects, is more refined. I used this synth a lot on Chronology and Revolution. These are the albums which spoke to people the least, but which were important in my career as they marked a period of flux where I still had a foot in analogue and another in what would go on to become digital.

Jean-Michel Jarre


Zenta: A Informática Esotérica

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